At present, there are more and more data products which use Universal Serial Bus (USB) interfaces. Such standard interfaces facilitate data transmission between various data products and have been developed in various different structural forms. For example, direct insert type interfaces are relatively common in USB flash disks (U-disk for short); lead wire type interfaces have become standard configuration in many data products; and turnover type interfaces are mostly used in network cards. With the development of electronic products, however, a plurality of data products may be plugged into one electronic product, thus interfaces of the data product are required to have flexible plug structures so as to avoid interference between them. However, if flexible plug structures are used, the stability and reliability of communication will be affected, or even failure will occur, resulting in damage to the interfaces.